Guys, I am in the situation where it looks as if I will have to run a USB "Normal" Rate = 12MBit/sec connection through a 3kV isolation block. Has anyone done this of has any ideas as to how easy it might be. The data is encoded NRZI with bit stuffing to prevent long runs of 1 or zero so a transformer may be adequate - but the control systems breaks these rules to identify control codes - I think. Also, one line of the differential pair is pulled high to indicate the data rate - so this would need to be detected & reinserted separately. It can obviously be done with sufficient complexity, but I am wondering if anyone has had success with a simple way? Thanks, Richard P -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.